Preheat the oven to 200°C / 400°F / Gas Mark 6.
Put the quinoa, water, lemon zest, sumac and thyme into a medium pan.
Bring to the boil then reuce to a simmer and cook, covered, until all the water is absorbed. Set aside.
Peel the red onion and slice into half moons. Peel and halve the butternut squash, take the seeds out, and roughly chop the flesh. Drain the butter beans and rinse throughly.
Put the sliced onion into a bowl and add 2 tsp of balsamic vinegar. Transfer them to one end of a lined baking tray, with the buternut squash at the other.
Roast in the oven fo 30 minutes. Leave the oven on as you will need it later.
Put half the quinoa mixture into a large bowl and add half the butter beans, the roasted re onions and the pasley. Mix well together.
Put the other half of the quinoa e onions and the parsley. Mix well together.
Put the other half of the quinoa an butter beans into a food processor and add the sun-dried tomatoes, roasted squash, sesame seeds, lemon juice, peeled garlic, olive oil, salt and the remaining tsp of balsamic vinegar. Blend until smooth.
Add the blended mixture to the bowl of quinoa and mix well. Shape into burger-shaped patties, using your hands.
At this stage he mixture should feel wet, but it will solidify once baked.
Put the burgers on a baking tray lined with baking parchment and roast in the oven for 35 minutes.
Serve topped with slices of ripe avocado, and with hummus or harissa alongside.